He observes that there are two cops on the film, and one gets people calmed down, and other one is Eric Casebolt:

An officer in McKinney, Texas, dashes down a sidewalk, losing his flashlight as he runs past a teenage videographer toward an emergency. Seconds later, the teen with the camera walks up to another officer, one who is standing with a group of kids. “I’m just saying,” the officer is saying in a calm, corrective tone that parents and school teachers everywhere will recognize. “Don’t take off running when the cops get here.”He thanks the videographer for returning the flashlight, then listens for a few seconds as the kids around him try to explain who was and was not involved in a prior incident. “Okay, guys, I appreciate that,” the as-yet-unidentified officer says. He responds to their concerns—that the police had detained the wrong people—by saying, “Okay, that’s what I’m saying. They’re free to go.” While not casual, the officer is composed. His tone is friendly and professional as he engages with the kids.Seconds later, another officer, Corporal Eric Casebolt, is shown interacting with some of the same kids. His angry tone and aggressive attitude stand in marked contrast to the first officer in the video. “Get on the ground,” he commands sharply while pulling on a young man’s wrist in a way that looks like he’s trying to force the man to the ground with a painful joint manipulation (technically a supinating wrist lock or, for martial arts enthusiasts, kote gaeshi). When that proves ineffective, he grabs the back of the young man’s head and shoves him down. “I told you to stay,” he yells, pointing a large metal flashlight at someone off camera. “Get your asses down on the ground.” Like the first officer, he lectures some of the kids about running from the police, but he takes a very different approach. “Don’t make me fucking run around here with thirty pounds of god-damned gear on in the sun because you want to screw around out here.” He is anything but composed, calm or professional. The two officers in this brief video represent two different policing styles, two different mindsets that officers use as they interact with civilians: the Guardian and the Warrior. As a former police officer and current policing scholar, I know that an officer’s mindset has tremendous impact on police/civilian encounters. I’ve described the Guardian and Warrior mindsets at some length here and here; for now, suffice to say that the right mindset can de-escalate tense situations, induce compliance, and increase community trust over the long-term. The kids interacting with the first officer were excited, but not upset; they remained cooperative. Had they gone home at that moment, they’d have a story for their friends and family, but it would be a story that happened to have the police in it rather than being a story about the police. ………Officers should also look out for each other, protecting their colleagues not just from harm, but also from lashing out in anger or frustration. Policing can be intensely stressful, and officers should be trained and encouraged to help their peers deal with stressful situations. When an officer is losing his cool, another officer will often be able to intervene, giving the first a chance to collect himself. That type of peer support isn’t part of modern police culture—particularly not when the officer losing his temper is a supervisor and union official like Corporal Casebolt—but it should be. A short video of officers in McKinney, Texas, shows us the avoidable results of an unnecessarily aggressive approach to policing. But in the same video, we can see a few seconds of policing the way the way it should be done.

Remember the old days, when people called members of the constabulary, "Peace Officer"?

A warrior cannot be a "Peace Officer". Their job is wage war against the enemy.

Peace Officers do not wage war against an enemy, the protect their fellow citizens.

In antiquity, when a "Warrior" took a town, he was supposed to take any male child that he found, and dash its brains out on the cobblestones.